Signaling.



R. A. FESSENDEN.

SIGN'ALING. APPLICATION man SEPT. 5, 1913.

1,182,843.` Patented May9,1916.

UNITED sTATEs PATENT oEEioE.

REGINALD A. FESSENDEN, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR T0 SUBMARINE SIGNAL COMPANY, OF WATERVILLE, MAINE, A 4COREQRA'IIOIT OF MAINE.

SIG-NALIN G.

Specication of Letters Patent.

Patented May 9, 1916.

Application led September 5, 1913. Serial No. 788,316.

To all/107mm t may conce/rn Be it known that I, REGINALD A. FESSEN- DEN, of Brookline, in the county of Norfolk and State of Massachusetts, a citizen ofthe Vnited States, have invented certain new and useful Improvements in Signaling, of which the following is a speciication.

My invention relates to the transmission and receipt of power, and particularly to power for signaling. and still more particularly, the directional transmission and receipt of sound signals in water and other media.

It has for its object increased eificiency in such apparatus and methods.

My invention will be understood by reference to the drawings in which-:-

Figure 1 is a diagram showing the location of the various apparatus on board ship; Fig. 2 is a view showing the various apparatus in diagram together with the electrical connections; Fig. 3 is a longitudinal -section of the brush at the change-over station; Fig. t is a corresponding' section of the switch at the indicator station, and Fig. 5 is a form of receiver which may be used if desired. l'leretofore in the practice of the art, direction has been found wirelessly, by comparing the strength of signals received on antennae in the form of vertical loops (Fessenden German Patent No. 225,256, J an. 14,

1907), or by comparing the ystrength of sig-v nais received on vertical antennae` (,Fessenden Il.' S. Patent No. 941,565, Nov. 30, 1909), or by comparing the strength of signals received on horizontalantennae, at varying angles with reference to the axis of the ship; or by signals transmitted through the air and receivedby'the ear, or on a single receiver, or by signals transmitted through water and received on two'microphones, the ship being swung till both microphones give the same intensity of sound.

Vlu the present invention the signals are transmitted and received through the water,

thereby avoiding the difficulties due to atmospheric disturbances met with in wireless methods, and the difhculties due to reflection and aerial dlsturbances when the signals are transmitted through air. It diifers, however, from former submarine methods in the following, among other particulars: 1. Instead of using two or more microphones whose comparative sensitiveness may not remain the same, .non-microphonic electric receivers are usedwhich` give a definite response to a. definite strength of signal. 2. While directionmay be located by swinging the ship till the-strengths of two signals are the same, direction may also be found by comparing the intensity of two signals. 3. Submarine sending apparatus is preferably used which sends out ksignals through a limited arc only, preferably about 120 degrees. 4. One sending apparatus and one 'receiving apparatus is preferably used to send and receive through each 90 degrees of the circumference, and about 15 degrees on eachside of the 90 degree are. 5. In fog or when otherwise desired, signals are sent automatically on each one of the four trans` mitters, each transmitter lsending a different signal.

In Fig. l', the ship is provided with four sets of apparatus, B, C, D and E, capable of acting both as transmitters and receivers,

for eXample,-the oscillators described in U. S. patent application, Ser. No. 744,798,-l

the conductors leading from these oscillators ruling -to a central station on the ship at y In Fig. 2, is the change-over station; J is the indicator station, both of these being located preferably in the pilot house or station A on board ship. F is a direct current genera-tor and G is an .alternating current generator.

The direct current generator F is connected with the field of the oscillators B, C, D and E by the wire which leads from one set of brushes to the field of each oscillator by means of the branches f1. Corresponding returns f2 lead t0 the wire f3 in which is a circuit closer f4 and which is bridged by one or more resistauces f5 which as shown comprise two incandescent lamps. The wire f3 continues to the other set of brushes at the generator F. I prefer that a certain amount of. current shoud always How through the fields of the oscillators to keep them warm, the full lield current being thrown in automatically as described below.

rlhe change-over station H comprises an insulated plate (not indicated). on which are mounted segments b, o, d and e. There is also a receiving segment 7c3. Between these segments are dead spaces its. Mounted on the center of the insulated plate is a rotatable brush or switch comprising two members which cross and are insulated from each other forming four arms 71 1, ,71,2 and ,31.3. On the plate are also mounted concentric metall-ic contacts forming segments of smaller radius than the segments, b, c, d, e and 7c3. The outer of these contacts comprises two segments, it* and h5. Within this is a second series of similar contacts ha and it? and within that an annular contact it". The segments ,7a4 and h5 and the segments h and la? are separated by dead spaces i210. The radius of the segments it* and h5 is substantially the length of the arm 71.1 of the brush. The radius of the segments it and k7 is substantially the length of the arm h2, and the radius of the inner circle la, is substantially the length of the arm h3 so that each of these arms will act upon its own set of contacts.

The indicator station J comprises an insulated plate (not indicated) upon which is mounted a metallic ring contact J1 outside of which is a circle comprising segments b2, 58, c2, c3, d2, CZ", e2 and e3. Outside of this circle of segments is a series of pins divided into four sets, numbered respectively to 29, 30 to 39, 40 to 4:9 and 50 to 59. Pins 2O and 29 are connected to wire b1 by branches o, 727 and the pins and 39 to wire e1 by branches c, c?, the pins 40 and 49 tov wire Z1 by branches de, Z7 and pins 50 and 59 to wire e1 by branches e, e7. Upon the center of this plate is mounted a rotatable switch comprising three separate but mechanically connected arms, y' being the longest arm, and reaching the outer circle )f the contacts 20, 30, etc., jl being in line with said erm but shorter in length to reach :he segments 52, c2, etc., and 7'2 being an arm it right angles to the other arms, long anough only to reach the circle J1. Nornally the arm i2 is in electrical contact with the arm j but by means of a push )utton located at ja the arm jz may be dis- :onnected electrically `from the arm y' and aonnected with the arm il.

The alternating current generator G has he usual brushes, one of which is connected )y the wire g with the segment 71.5 in the i.bange-over station H. The other brush is :onnected by the wire g1 through a key g2 Vith the segment fte. The contact 7) at this :tation lis connected by the wireI b1 with the Scillator B. rlhe contact c is connected by he wire c1 with the oscillator C. The conmeas@ tact d is connected by the Wire d1 with the oscillator D, and the contact' e is connected by the wire e1 with the oscillator E. The circle )5,9 at the change-over station is connected with all the oscillators by means of the return-wire g3. To send a signal by this means, say from the oscillator B, on the port bow of the ship (see Fig. l) the switch at station H being in the position shown in Fig. 2 (the circuit closer f4 being first closed to excite the fields in the various oscillators to their maximum and the circuit closer or key g2 also being closed), the course of the current from the generatorG is through the wire g, segment h5. arms k1 h, contact I), wire b1 and the oscillator'B, from thence to the wire g8 and circle k", arms k3, h2, segment wire g1 and its circuit closer to the generator G. A similar circuit can be 'traced from each of the contacts 0, (Z and c to its oscillator C, D and E upon the movement of the switch to such contact.

l 'The switch il, k1 may be turned about its center automatically and at each Contact it may give out a series of predetermined signals,-the signals. for instance. of Contact c sent by the oscillator C located on the port miarter being, for example. a pair of dots.

When contact 7) is used the oscillator B on the port bow will gire out a pair of dashes. When lcontact d is used the oscillator D on the starboard bow will give say three dots and a dash, and when lthe Contact e is used the oscillator E on the starboard quarter will give a signal consisting of five dots. Mechanism :for moving the arms automatically and mechanisms for automatically making and breaking a circuit are well known in the art and hence need not be described. lf the switch member be stopped lat any one of the segments, i3. c, d or e, the key g2 may be -used to send out messages by the Morse or other codes by means of the oscillator in circuit.

The receiving apparatusis out of circuit until in the rotation of the switch at the change over station the arm 7L reaches the segment lo. This brings into circuit a telephone K connected by one wire 7c with the segment k and by another wire k1 with the segment ILT.' Under these circumstances. that is, during the receiving operation, the

generator G is cut out from the circuit and. y

sound'waves striking the side of the ship cause the vibration of such of the oscilla- 'tors as are in reach. which vibration excites a current in whatever circuit is closed. ForV example, suppose the parts arelm the posi- V tion shown 1n Fig. 2, where the arm j rests and the arm y' and from thence through the arm jg to the circle J1, thence by the wire k2 to the segment gacross from I.4 by means of the arms 71,1, k to the segment 7c3, thence by the wire 'i to the telephone K, b v the wire k1 to the .segment LT. from LT by the cross arm 71,2, It to the circle hg and thence by the wiremg3 back to the oscillator B.

Each set of contacts 2O to 29, 30 to 39, etc.,

5 is divided into two divisions containing respectively four and six contacts. The contacts of each smaller division are connected by resistances and the contacts of each larger divison are connected by resistances as shown. "Thus, for example, the oscillator wire /l is connected with the contact division 2.9-24 by the wire 67 and with the contact division --23 by the wire 736.

T he segments 772, b3, c2, c3, d2, d3 and e2. c are provided for the purpose of making a comparison between the sounds received b v one oscillator and ythe sounds received by one of the adjacent oscillators without changing the position of the switch j, jl, jg. For this purpose the contacts Qty-23 .are connected by the wire b4 with the segment b3 which is connected by the wire b5 with the 'segment b2. The contacts 30-33 are connected by the wire c* with the segment (#3 which is connected by the wire c5 with the segment c2, etc.

When the arm j rests on contact 20, as in Fig. 2, the oscillations of the oscillator B on the port bow are heard. Upon the depression of the button js, arm jz is disconnected electrically from .arm j and is connected with arm y, thus bringing the oscillator D into circuit through segment d2, wire d5, segment ds and wire (Z4, which is connected with contact 40. from which the remainder of the circuit can easily be traced through the receiver K. This enables the oiicer, by merely depressing the push button. to compare the strength of the vibray tions on the two sides of the bow.` A similar comparison may bel made between the vibrations of any adjacent pair of oscillators. Bearing in mind that, in receiving, the oscillators respond in proportion to the strength of the sound waves, and that the effect of two sets of vibrations of diferent strengths (i. e. coming from transmitters or similar oscillators located at diierent distances, for example, upon different parts of an approaching ship) may be equalized at the receiving point by the introduction or' resistances properly standardized for the purpose, so as to reduce the effect of the stronger vibrations to that of weaker, a method will now be described whereby the course of an approaching ship may be determined as well as the position of the observing ship with relation thereto.

The standardization of the apparatus,

' xhat is to say, the adjustment of the resistances for a particular ship may be obtained especially by swinging the ship (as in standardizing compasses) with reference to a source of sound when directionv is known. Suppose the source of the sound is on board of another vessel which is sending out the standard signals, each oscillator sending its own signals as referred to above. The

Aswitch at station H being on the segment k3, the ship is receiving, and the oiiicer byi turning the indicator switch handle at J onto 2O listens in on oscillator B, then he listens to oscillator C on the port generator, etc., to determine the general direction from which the sound proceeds. Suppose he hears pairs of dots and also dashes while l-istening in on B. He knows that the other ship has her port side toward him. He hears the dashes loudest; therefore heknows he is on her port bow. He turns the handle of the switch at J to the left over the contacts 21, 2Q, etc., listening at each contact until the dashes are reduced in intensity which may be at the contact 22) then knows that he is 9.0 degrees oi the port bowv of the other ship. This gives the course the yother ship is steering.

The .officer next proceeds to find the direction of the other ship. He hears the dashes while listening in on contacts 20' and 4:0, that is. on oscillators B and D. He therefore knows that the other ship is on his bow. He' hears the dashes strongest on oscillator D, and knows the ship is on his starboard bow. He turns the switch so that the-intensity of the dashes when heard on some contact such as 41 are of the same 'strength as the-dashes heard when the push button is depressed, that is, when listening 011 oscillator B. From the standardization of the apparatus he knows that this poi-nt corresponds to an angle of degrees. He has thus learned therefore that there is a ship 30 degrees on his starboard bow and that this ship is steering in such a course that he is 20 degrees on her port bow. form an approximate estimate of her distance by means of the strength of the signals received.

Insteadv of using the oscillators as receivers as Well as senders, other forms of receiver may be used, provided they are of the non-microphonic kind. z'. e.. perfect or fixed contacts. Such a receiver is shown in Fig. 5 and consists of a condenser formed of very thin sheets of soft rubber or mica and tin f" He can also v condenser. and current liows from the battery 62 through the leads 63, 64 and the receiver 65, and the signal is reproduced in the receiver 65. The sensitiveness may be as great as desired by increasing the size of the condenser in area and thickness up to quarter ware length, approximately, and in capacity by diminishing the thickness of the mica or soft rubber plates. or in power by increasing the voltage of the battery 62.

:0 The reactances of the condenser and receiver should be equal and opposite in sign so far as possible, 2'.. e., the real parts should be equal and of the same sign., and the imaginary parts should be equal and of opposite :5 sign for the desired signal.

VIn place oi mica or softrubber other materials may be used provided the velocity of compressional wave propagation 1s high and preferably of the order ot a mile `0 per second. If the velocity is less, the thick'- ness of the condenser must -be reduced 'so that it does not exceed approximately 'a quarter wave length of the signal.. Or if 1t does, then alternate sections, going away 5 from the side of the ship, should be connected oppositely to each other if in series, or oppositely to the receiver if in parallel so that their eiiect willv not 'neutralize each other.

0 In place of the tin foil sheets of the condenser shown in Fig. 5. sheets or disks of thin sheet iron or nickel may be used, preferably radially slotted, and the receiving ciiect obtained bythe action of the sound 5 waves in altering the relative position of these iron disks, and thereby increasing or decreasing the reluctance of a magnetic circuit comprising as one element the cylinder made up of said thin iron disks and 3 the separating material. mica. paper, rubber,

etc.. between them.

It is desirable that the switch f4 be controlled by a. spring which will keep it normally closed and being forked in the custo- 1 mary way to allow the receiver K to be hung from it when the apparatus is not in use so as to open it. thus throwing the current from the dynamo l" through the resistances f5. lVhen the apparatus is in use the receiver must be removed from the switch to allow the full direct current to pass to the oscillators. sstated above. it is preferable that a partial direct current flow continually through the oscillators to i keep them warm.

messes What I claim as my invention isz- 1. The method of determining the course of a ship which consists in transforming the energyof sets of sound impulses transmitted by a plurality of Sounders on said ship into electrical impulses originating in a single source atl areceiving station, and

equalizing the strength rof the electrical. im-

mitted by a, plurality of Sounders on said ship into electrical impulses originating in a single source at a receiving station and reducing the strength of thel electrica impulses originating from the stronger set of sound impulses by introducing resistances at said receiving station in amounts predetermined according to the relative positions of'k sources of sound impulses to said receiving station.

3. The method of determining the direction of a ship from a receiving station which consists in transforming s ound impulses originating on said ship into electrical impulses at a plurality of sourcesv at said re' ceiving station and equalizing the strength of said electrical impulses by throwing resistances into thel path of stronger impulses,

said resistances being predetermined according to the relative positions of the source of electrical impulses.

4.111 a system of sound signaling, a plurality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatus being adapted to act over -a limited field, and being located with relation o each other whereby said fields will over- 5. ln a system of submarine sound signaling, a plurality of apparatuses, adapted to emit sound and to detect emitted sounds,

each apparatus being adapted to act over a limited field, andbeing located with relation to each other whereby said fields will overlap.

G. In a system of sound signaling, a plurality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatus being adapted to act over a limited field. and being located with relation to each other whereby said lields will overlap. and means for putting in operation any desired apparatus.

7. In a system of submarines sound signaling. a plurality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatus being adapted to' act over a limited field, and being located with relalil() v sired apparatus, and means for changing rality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatus being adapted to act over a limited field, and being located with relation to each lother whereby said fields will overlap, means for putting in operation any dethe function of any desired apparatus from sending to receiving, and from receiving to sending.

9: In a system of submarine sound signaling, a plurality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatus being adapted to act over a limited field, and beinglocated withrelation to each other whereby said fields will overlap, means for putting in operation any desired apparatus, and means for changing the function of any desired apparatus from sending to receiving, and from receiving to sending.

10. In a system of sound signaling, a plurality `of apparatuses adapted to emit sound and to detect emitted sounds, each apparatus being adapted to act over a limited eld, and being located with relation to each other whereby said elds will overlap, means for putting in operation any desired apparatus,

and means for operating said apparatus from a plurality of stations.

11. In a system of submarine sound signaling, a plurality of apparatuses, adapted to emit sound and to detect emitted sounds, each apparatusbeing adapted to act over a limited field, and being located with relation Y to each other whereby said fields will overlap, means` for putting 1n operation any desired apparatus, and means for operating said apparatus from a plurality of stations.

12. In a signaling system, a switchboard having a series of sending contacts, a series of oscillators one connected to each of said contacts, said switchboard also having a receiving contact, a receiver connected to said receivingr contact, a sourceof electricity and a switch adapted to connect said source of electricity to said oscillators and complete a circuit through said oscillators `and to disconnect said source of electricity from said oscillators and to close a circuit through said oscillators and said receiver.

13. In a signaling system, a switchboard having a series of sending contacts, a sending mechanism connected to each contact, a common source of electricity connected to each sending mechanism and forming a part thereof, a receiving mechanism, a receiving contact connected thereto and located at 'said switchboard, a receiver connected to said receiving contact, and a switch adapted to connect each sending contact with said source of electricity and also adapted to connect said. receiving contact withA saidl receiver and break the contact between said sending mechanism and said source of electricity.

14. A signaling system comprising a plurality of receiving mechanisms, a receiver connected thereto, and a switchboard provided with a plurality of contacts arranged in sets, each receiving mechanism being adapted' to be connected with its own set of contacts, resistances connecting certain of the contacts in each set, means for connect- .fing any one of said contacts with said receiver, a sending mechanism, and means for shuntmg out said switchboard and simultaneously energizing said sending mechanism.

15. A signaling mechanism comprising a plurality of receiving mechanisms, a receiver, and aswitch-board provided with a plurality of contacts arranged in sets, each receiving mechanism being adapted to be connected with its own set of contacts, resistances connecting certain. of the contacts of each set, a composite switch comprising members adapted to connect each of two sets of contacts in turn with said receiver, whereby the vibrations of two,receiving mechanisms may be compared.

16. A signaling system comprising a plurality of receiving mechanisms, a receiver and a switchboard provided with a plurality of'contacts arranged in sets, one set for each receiving mechanism, resistances connecting certainy of the contacts in each set, and a switch adapted to connect any one of said contacts with said receiver.

17. A signaling system comprising a plurality ol combined sending and receiving mechanisms, a. source of electricity and a receiver' common to all the receiving mechanisms, a switchboard comprising a plurality of contacts, one connected with each sending mechanism and one connected with said receiver and a switch member adapted to engage each of said sending contacts to connect said source of electricity thereto and alsoadapted to engage said receiving contact whereby it will disconnect said source of electricity from said sending contacts Aand connect said receiver to said receiving Vrality of sending and receiving elements, a

receiver, a switchboard having contacts, a

source of electricity, a switch adapted to connect said source of electricity with any one of seid sending and receiving elements and also to disconnect said source 'of elec- 'tricity therefrom and connect said receiver to anv one of said Sending and receiving elements, n second switchboard having a plurality of contacts connected to each senmem@ 

